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How to Keep Captive Killer Whales Happy
A baby killer whale swims with its mother Kasatka on Dec. 21, 2004, at Shamu Stadium at SeaWorld Stadium in San Diego, California.
Credit: SeaWorld via Getty Images

Should killer whales Skype? A new study suggests that virtual links between captive orca populations might be one way to improve the lives of these marine mammals.

The keeping of orcas, or killer whales, in captivity has been a matter of public controversy, especially since the release of the documentary "Blackfish" in 2013. The film centers on the 2010 killing of a SeaWorld trainer, Dawn Brancheau, by a captive killer whale that had been captured from the wild in 1983. (That killer whale, named Tilikum, died on Jan. 6, Live Science reported.)

As a result of the public outrage following the documentary, SeaWorld announced in March 2016 that it would shut down killer-whale shows in its parks, as well as its orca breeding program. But orcas live for decades (and some have been known to live past 100), and there are dozens in captivity that will remain at SeaWorld (and other captive-breeding establishments) for the rest of their lives.

Now, two researchers at the University of Glasgow in Scotland have some suggestions for how to improve these orcas' lives.

The suggestions go way beyond offering orcas more toys and activities. One idea is to establish audio communication channels between different captive populations — and even wild populations — so they can "talk" to each other. Another is to establish feeding systems that require whales to work together to get food, as they do in the wild.

"We are at a stage where, for the most part, the physical welfare of animals in captivity is good and often a good deal better than in the wild," said animal welfare expert Graham Law, one of the authors of a paper listing the suggestions in the journal International Zoo Yearbook. "However, the psychological welfare is an area that needs more work." [Orca Gallery: See Gorgeous Photos of Killer Whales]

Whales' psychological health is at the center of the controversy over Brancheau's death. A male orca named Tilikum dragged Brancheau into the water after a show. As Outside magazine reported, Tilikum's early years were traumatic. He was captured and taken from his pod at age 2. (In the wild, male whales typically stay with their mothers for the rest of their lives, and a son's survival depends on his mother well into adulthood.) The young whale then was kept in a barren concrete pool in Iceland for a year before being transferred to a now-defunct marine park in British Columbia. There, Tilikum was bullied by two dominant females. In 1991, the three understimulated whales killed a part-time trainer who slipped into their pool, Outside reported.

Tilikum was then sold to SeaWorld, where, Outside reported, he had better care but was still harried by dominant females. In 1999, Tilikum was involved in the death of a man who snuck in after hours to swim in the orca pool. (It isn't known whether Tilikum killed the man directly, though he did mutilate the man's body.)  

"Tilikum is basically psychotic," Ken Balcomb, executive director of the Center for Whale Research, told Outside magazine. "He has been maintained in a situation where I think he is psychologically unrecoverable in terms of being a wild whale."

Though there are many arguments over whether killer whales should be kept in captivity, the fact is that they are already there, Law told Live Science. As of 2016, there were 56 captive orcas around the world, according to the journal International Zoo News. At some point, Law said, there may be hard decisions to make about whether captivity might save the species. [Marine Marvels: Spectacular Photos of Sea Creatures]

"The resident population of killer whales around Scotland are not doing very well, and soon they may be extinct" due to high levels of polychlorinated biphenyls (PCBs) in their environment, Law said. "We do not know what species we may need to protect in captivity in the future," he added. "We should, however, where possible, be aware of the best methods to do so."  

Law and his colleague Andrew Kitchener, principal curator of vertebrates at the National Museums Scotland, focused on social, feeding, fitness and environmental recommendations for the care of killer whales. These recommendations have not been tested, they cautioned, but all are based on mimicking the whales' activities and environment in the wild.

Socially, the researchers suggested, killer whales might benefit from communication with far-flung brethren. Orcas are vocally complex and can even learn new "dialects." Satellite uplinks between marine parks could connect disparate groups, Law and Kitchener wrote. Strange as it might sound, zoos have used sounds to promote natural behavior before, Law said. In 1989, researchers reported in International Zoo Yearbook that they'd used recorded gibbon calls to prompt a pair of gibbons in a London zoo to make their own territorial cries and to mate. The sound of what seemed to be nearby gibbons appeared to urge the primates to protect their territory and reproduce.

Animals other than orcas also might benefit from more enriched soundscapes, Law said. For example, lions communicate across prides with loud roars, and leopard calls seem to be full of information about the caller's identity, he said.

"We should think more about how unnatural it is to keep zoo animals in acoustic isolation," Law said.

The researchers also recommended different methods of feeding that would require orcas to take an active role in finding food. Motion-sensor feeders could be programmed to release treats after whales perform a task. Methods that require whales to work together could mimic the requirements of hunting as a pod in the wild. Orcas are known to be clever hunters: They make waves to wash seals off ice, they eavesdrop on prey and they even set traps.

Training could engage those sharp killer-whale brains, and build stamina. Law and Kitchener suggested training whales to hold their breath for long periods, thus simulating the deep dives the whales do in the wild. They also suggested more naturalistic features in tanks, like kelp (real or artificial), artificial boulders and wave-making machines. Acoustic materials could be varied in tanks to give whales something to echolocate off of, the researchers wrote. Tapes of ocean sounds could be played to stimulate whales' senses.

All of these ideas, Law said, need to be tested scientifically. The public debate over killer whales in captivity is highly polarized, he said, but trainers at SeaWorld and other marine parks are very enthusiastic about improving the welfare of their animals.

"As far as I am aware, husbandry changes were already in the pipeline by a number of organizations that keep orca to create better conditions for them," Law said. "I hope that the public will support any positive attempts to make things more interesting and challenging for animals in captivity."

Original article on Live Science.